Hello,

I have over 50 subdomain under one record setting.

domain.com points tp A record 123.456.789.10

abc.domain.com points to A Record 123.456.789.10 TTL 120
def.domain.com points to A Record 123.456.789.10 TTL 120
ghi.domain.com points to A Record 123.456.789.10 TTL 120
jkl.domain.com points to A Record 123.456.789.10 TTL 120
mno.domain.com points to A Record 123.456.789.10 TTL 120

etc.

In IIS, I've created abc.domain.com etc. and point to it's correct directory.

Everything is working fine. My only problem is that after 2-3 mins, I revisit abc.domain.com, def.domain.com etc. Some resolves, and some doesn't. Also sometime my domain isn't accessible through www., I can only access is through domain.com

I read on using the wildcard *.domain.com. Gave that a try and I'm still getting DNS not resolving issue every. After many hours of testing, It resolves for 3min and doesnt for another couple of minutes, then goes back to resolving again.

Please suggest what is going on

Thanks

Hi Jesper, thanks for the reply and the help. I hope you can give me some more advice as this is really frustrating for me to understand the issue.

I did as you told with the nslookup in SIMPLE DNS PLUS.
It seems every attempt does resolve.

But what I further notice is when I attempt to visit one of the subdomain.domain.com through a browser that gives me an error page. I quickly ping the subdomain.domain.com and did not get any IP resolve. What could this possible mean?

This issue happens on all five 5 computers at different location. All the 5 computer have reported the subdomain.domain.com comes up and goes away repeatedly.

Thanks